Created by LABScI at Stanford
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Potential and Kinetic Energy: Roller Coasters
Student Version
Key Concepts:
• Energy is the ability of a system or object to perform work. It exists in various forms.
• Potential energy is the energy an object has inside a force field due to its position. In the
roller coaster’s case, the potential energy comes from its height because the Earth’s force
of gravity is acting on it. Roller coasters are able to move their passengers very rapidly up
and down the hills because the cars gain a large amount of potential energy from the very
first hill.
• Kinetic energy is mechanical energy that is due to motion of an object.
• Thermal energy is energy due to the heat of a system or object. Energy can be converted
to heat through frictional dissipation.
• Friction, or frictional dissipation, is a phenomenon in which mechanically useful energy,
such as the motion of the roller coaster, is converted to mechanically useless energy, such
as heat or sound. Friction acts on all moving objects, and it is the reason that a ball rolled
across an open space will eventually slow down and stop.
• “Conservation of Energy” is a fundamental principle that energy cannot be created or
destroyed. Rather, it is transferred between different forms, such as those described
above.
